Walnuts (Juglans regia) aren’t just a popular ingredient in desserts, pasta dishes, and salads. For people, walnuts are an excellent source of antioxidants that protect cells from damage and help improve memory and brain health. The fiber and omega-3 fatty acids in walnuts and other tree nuts can help to lower cholesterol, potentially reducing the risk of cardiovascular disease in humans.
As you’re enjoying the satisfying crunch of a walnut, you might be wondering if it can be a healthy snack for your dog, too. Although it may be technically safe for dogs to eat a few walnuts (especially if they are store-bought and unsalted), walnuts are not the best choice for your dog. Walnuts can be a choking hazard for dogs and, when eaten in large quantities, can lead to a potentially life-threatening condition called pancreatitis.
Can Dogs Have Walnuts?
Unlike almonds and cashews, which can dogs can safely consume when fed occasionally and in very small quantities, walnuts are best to avoid altogether. The good news is that if your dog accidentally ingests a walnut or two, they’re unlikely to suffer ill effects.
Are Walnuts Bad for Dogs?
It depends on the type of walnut, the presence of mold, and the amount consumed. English walnuts are the ones you typically find in the grocery store aisle. These walnuts aren’t necessarily toxic for dogs, but it’s wise to avoid feeding them to your dog.
Another type is the black walnut (Juglans nigra), which is a species native to North America. Though people don’t commonly eat this type of walnut, black walnuts are still extremely toxic to dogs; along with pecans, black walnuts may contain a toxic chemical called juglone.
For dogs (and horses), consuming juglone can cause gastrointestinal (GI) problems like upset stomach, vomiting, and diarrhea. Depending on the amount your dog ingests, GI symptoms can last a few hours or worsen, if left untreated. Accordingly, it’s important to seek veterinary care immediately since a dog’s condition can rapidly deteriorate; in some cases, juglone consumption could be fatal.
Like other tree nuts, walnuts are susceptible to mold due to exposure to moisture and high temperatures during harvesting and storage. Mold can grow on the shell or kernel. A particular concern regarding walnuts for dogs is that walnuts grow a type of mold called Aspergillus flavus. This produces aflatoxin, a natural poison that can also affect corn, rice, and peanuts.
For dogs, ingestion of aflatoxin can lead to decreased appetite, vomiting, and even death. In addition, moldy walnuts may contain a mycotoxin called penitrem A, which can lead to muscle tremors, seizures, and vomiting. Be sure to contact your veterinarian immediately if your dog accidentally eats a black walnut or moldy walnut.
Pancreatitis in Dogs and Other Health Concerns
Because walnuts are high in oil and fat, consuming more than a handful can put your dog at risk for developing pancreatitis. After consuming fatty foods, digestive enzymes can become activated before the food reaches the small intestine. This can result in inflammation and damage to the pancreas and surrounding organs. If this happens, it’s important to monitor your dog for symptoms like abdominal pain, weakness, dehydration, and diarrhea and to take them to the vet for early diagnosis and treatment.
Walnuts can also be a choking hazard or cause intestinal blockages, especially in small dog breeds or if the walnut is still in its shell. Walnuts that are salted or contain seasonings with ingredients like onion or garlic can be toxic for dogs. In any case, there are plenty of foods your dog can enjoy besides walnuts.